Photo coding: a pragmatic approach to measuring intervention fidelity in a pharmacy system re-design

Area of Science:

• Health Services Research
• Human Factors Engineering
• Pharmacy Practice

Background:

• Measuring intervention fidelity is crucial for transitioning evidence-based practices into community settings.
• Traditional fidelity measurement methods (self-report, direct observation) have limitations in cost, time, and external validity.
• Photo coding presents a pragmatic, novel approach to observational fidelity assessment.

Purpose of the Study:

• To evaluate the feasibility and effectiveness of photo coding for measuring intervention fidelity.
• To assess the fidelity of the Senior Safe™ intervention, aimed at improving over-the-counter (OTC) medication safety for older adults in pharmacies.
• To identify components supporting or hindering intervention uptake and sustainability.

Main Methods:

• The Senior Safe™ intervention involved re-shelving OTC medications by safety level and adding clear signage, guided by human factors principles.
• Pharmacy photos were taken at two time points (T1, T2) to assess intervention layout and medication categorization fidelity using constructed codebooks.
• A high-fidelity standard of ≥80% concordance was established; coding was performed by research assistants and PharmD students.

Main Results:

• Fidelity was assessed across 67 pharmacy sites implementing Senior Safe™.
• All sites achieved ≥80% fidelity for the Layout Codebook at both time points.
• Medication Categorization fidelity showed a statistically significant decline, with 97% high fidelity at T1 versus 85% at T2.

Conclusions:

• Intervention fidelity measurement is vital for assessing the sustainability and successful community transition of evidence-based practices.
• Photo coding provides an innovative method to measure intervention fidelity, revealing layers of concordance and discordance.
• Organizations should investigate intervention fidelity to identify adaptation needs and ensure successful implementation.